The Buffy-Angel Breakup
The idea is stupid at first but the show's writers have managed to redeem it by introducing interesting characters, injecting dialogue with unexpected burst of comedy and writing good stories. Buffy grew so much, it gave birth to a whole new series.
Angel is Buffy's ex-boyfriend played by David Boreanaz is a vampire with a soul. After the break-up, he goes to Los Angeles with Charisma Carpenter's Cordelia where he becomes a private investigator to help people.
With the exit of Angel from Buffy's life her series seemed to have been drained. She goes off to a nearby college where the ghouls seem to have followed. Why don't they just stay in Sunnydale. Their lives are much easier there since there's no more Slayer to worry about. The Hellmouth, which is still under Buffy's high school, has been relatively quiet. Buffy's problems now are juvenile vampires and demons in her college.
Meanwhile Angel has his hands full in LA. The bad guys here seem to be more organized. They even have their own law firm. Cordelia has become a psychic-Angel's direct link to The Powers That Be. Aside from managing his finances, she is his guide to the greater scheme of things. Because Angel is more concerned with helping people than just slaying, he faces more dilemmas and has greater purpose than his ex.
Buffy's circle of friends is now a boring bunch. Without Seth Green's apathetic Oz, it just isn't the same. They're still funny in the face of danger but together they just hang out without any relational conflict. The addition of Spike to the cast provides a much needed break from the friendly atmosphere.
Cordelia, Wesley and Angel, on the other hand, are at each other's necks almost all the time. This increases the quality of the insults they throw at each other.
As for post-breakup romances, Buffy is luckier. Her new boyfriend is a college anti-demon commando whose base is under their university. Angel has no one yet but it seems a romance is building slowly but steadily between him and his blond police friend. He may be taking more time with his rebound but it is good to see his tastes have not deteriorated.
But not all is lost with Buffy the Vampire Slayer. The series still has its greatest asset: Sarah Michelle Gellar. Watching her is entertainment enough. Its fight scenes along with Angel's are still the best on primetime TV. It was once the most refreshing and mature teen series. Its breakup with Angel however caused it to regress and lose unfortunately its better half.